8 August 2019 - - The US Food and Drug Administration has granted orphan drug designation to its lead product candidate, STK-001, an investigational new treatment for Dravet syndrome, US-based biotechnology company Stoke Therapeutics, Inc., (NASDAQ: STOK) said.

Dravet syndrome is a severe and progressive genetic epilepsy, characterized by frequent, prolonged and refractory seizures beginning within the first year of life.

The effects of the disease go beyond seizures and often include cognitive regression or developmental stagnation, ataxia, speech impairment and sleep disturbances.

Compared with the general epilepsy population, people living with Dravet syndrome have a higher risk of sudden unexpected death in epilepsy, or SUDEP.

Approximately 85% of Dravet syndrome cases are caused by spontaneous, heterozygous loss of function mutations in the SCN1A gene.

This gene encodes the voltage-gated sodium channel type 1 alpha subunit (NaV1.1). Currently available treatments do not address this mutation, the underlying cause of Dravet syndrome.

The FDA's Office of Orphan Drug Products grants orphan status to support the development of medicines for safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the United States.

Orphan drug designation entitles recipients to various development incentives, including tax credits for qualified clinical testing, an exemption from FDA application fees, and a seven-year period of marketing exclusivity in the United States, if the drug is approved.

Dravet syndrome is a severe and progressive genetic epilepsy characterized by frequent, prolonged and refractory seizures, beginning within the first year of life. Dravet syndrome is difficult to treat and has a poor long-term prognosis.

Complications of the disease often contribute to a poor quality of life for patients and their caregivers. Compared with the general epilepsy population, people living with Dravet syndrome have a higher risk of sudden unexpected death in epilepsy, or SUDEP.

Dravet syndrome affects approximately 35,000 people across the United States, Canada, Japan, Germany, France and the United Kingdom, and it is not concentrated in a particular geographic area or ethnic group.

STK-001 is an investigational new medicine for the treatment of Dravet syndrome. Stoke believes that STK-001, a proprietary antisense oligonucleotide, has the potential to be the first disease-modifying therapy to address the underlying genetic cause of Dravet syndrome.

STK-001 is designed to upregulate NaV1.1 protein expression from the non-mutant (wild type) copy of the SCN1A gene to restore physiological NaV1.1 levels, thereby reducing both occurrence of seizures and significant non-seizure comorbidities. Stoke has generated preclinical data demonstrating proof-of-mechanism for STK-001.

Stoke Therapeutics, Inc. (NASDAQ: STOK), is a biotechnology company pioneering a new way to treat the underlying causes of severe genetic diseases by precisely upregulating protein expression to restore target proteins to near normal levels.

Stoke aims to develop the first precision medicine platform to target the underlying cause of a broad spectrum of genetic diseases in which the patient has one healthy copy of a gene and one mutated copy that fails to produce a protein essential to health.

These diseases, in which loss of approximately 50% of normal protein expression causes disease, are called autosomal dominant haploinsufficiencies. Stoke is headquartered in Bedford, Massachusetts with offices in Cambridge, Massachusetts.